1. Field of the Invention
The subject matter of this invention relates generally to puffer circuit interrupters, and relates more specifically to supports for gas condensers in circuit breaker apparatus and to current carrying contacts in circuit breaker apparatus.
2. Description of the Prior Art
It has been known for some time to utilize gaseous environments in circuit breaker apparatus. U.S. Pat. No. 2,757,261 issued to Lingal et al on July 31, 1956, U.S. Pat. No. 2,798,922 issued to Lingal et al on July 9, 1957, U.S. Pat. No. 2,809,259 issued to Baker et al on Oct. 8, 1957 and U.S. Pat. No. 2,733,316 issued to Browne et al on Jan. 31, 1956 all teach sulfur hexafluoride gas environments for circuit breaker apparatus. The preceding patents teach a relatively static gaseous environment in which the insulating and arc extinguishing qualities of sulfur hexafluoride gas are utilized. U.S. Pat. No. 2,824,937 issued to A. P. Strom on Feb. 25, 1958 and U.S. Pat. No. 2,748,226 issued to MacNeill et al on May 29, 1956 teach the utilization of a blast or flow of sulfur hexafluoride gas for extinguishing an arc. Recently, puffer type compressed gas circuit interrupters have been taught, such as by U.S. Pat. No. 3,852,551 issued Dec. 3, 1974 to C. M. Cleaveland. In the latter case, a piston is mounted internally to an elongated circuit breaker apparatus to operate in conjunction with the operating mechanism for the contacts of the circuit breaker apparatus to provide a puff or jet of gas to the region of the arc during the contact opening operation of the circuit breaker. It is known to use gas condensers with circuit breaker apparatus. The condenser takes the heated gas from an arc extinguishing operation and cools it thus condensing water out of it and reducing its pressure and temperature. The gas is then vented to other portions of the circuit breaker apparatus at reduced pressure and reduced temperature for containment. In the past, the condenser or gas cooler, as it is sometimes called, was contained within a cylindrical shell which had holes disposed therein for venting the exit gas from the condenser to the region of containment. The holes, however, provided regions of greatly restricted gas passage. In addition, the bulk of the condenser enclosure represented a significant amount of metal since the holes represented only a relatively few openings therein. Furthermore, the condenser was formed of one single piece of material requiring a relatively complex manufacturing operation. Typically, the condenser had to be cut, machined, and drilled. Furthermore, the condenser was usually interconnected with flexible fingers which acted as the main contact fingers for the circuit breaker apparatus. The load current flows through the fingers and into the main body of the condenser enclosure where it flows past the holes toward the main terminal. It would be advantageous if a condensing support arrangement could be found which combined the support capabilities of the drilled condenser and the current carrying capabilities of the flexible fingers. It would be further advantageous if the condenser would be formed from a number of similar parts so that if one of the parts was defective or otherwise rendered inoperable, only that part would have to be replaced rather than the entire condenser. It would be further advantageous if the gas venting characteristic of the condenser enclosure was enhanced by the utilization of more openings and by the distribution of the pressure and heat dissipating characteristics thereof.